THE COMMERCIAL SPONGES AND THE SPONGE FISHERIES. 507 
A somewhat different aspect is presented by the proposition to close the 
grounds in rotation for periods of a year or upward. This would tend to 
intensify the fishery on the open grounds but would compensate for this by 
providing periods of rest, recuperation, and growth. By periodically closing a 
portion of the grounds for terms of say two years, there would be given to 
many of the small sponges already set an opportunity to grow to marketable 
size, the sponges already marketable would increase very materially in size, 
weight, and value, and these two would in turn result in the production of a 
larger number of embryos and a heavier set of young. Notwithstanding that 
many of the spongers and others interested in the business believe to the contrary, 
a period of two years is not sufficient to produce a merchantable sponge from the 
egg, and the earlier set of the closed period would not be ready to market until 
a year or two after the area was again opened to fishing. Even upon the 
impossible assumption that all marketable sponges were removed during the 
first open year, if the young were properly protected in accordance with previous 
suggestions the good effects of the closure would be apparent over a term of 
several years. 
The practical impediments to the application of this system of protection to 
the waters of Florida lie mainly in the necessity for making the required sub- 
divisions of the grounds rather small and generally distributed, and the conse- 
quent difficulty in securing its enforcement. It would not be feasible, for 
instance, to close the Bay grounds north of Cedar Keys and open them south of 
that place for the reason that the water might be turbid in the latter area while 
clear in the former, to the utter prostration of the fishery and the ruin of those 
engaged in it. To guard against such contingency it would be necessary to 
divide the whole area into transverse strips, say 10 miles wide, closing alternate 
zones or every third zone, as the case might require, leaving the others open. 
It would be necessary to mark these areas adequately with buoys and to estab- 
lish a patrol to enforce respect for the regulations. Moreover, as most of these 
waters are outside of marine jurisdiction, it would appear possible to make the 
regulations effective to our own fishermen only, though the distance from foreign 
ports would probably act as a geographical deterrent to the depredations of 
foreign vessels. In any event the regulations would be difficult to enforce even 
with the assistance of several guard boats. ‘This is probably the best and most 
effective type of close season, though presenting practical difficulties of enforce- 
ment; but it also is in essence a restriction on the intensity of the fishery and 
consequently on the yield, and whether it would add materially to the pro- 
ductiveness of the long-used hooking grounds is a matter of grave doubt; 
however, it might operate as insurance against ultimate depletion. It is prac- 
tically the method which nature already enforces in places by prolonged periods 
